Coins were developed as a medium of exchange because other items like cows, grain, and land were more difficult to move from place to place true or false?

Light that is polarized along the vertical direction is incident on a sheet of polarizing material. only 96% of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. no light passes through the second sheet. what angle does the transmission axis of the second sheet make with the vertical?

The slope of a velocity time graph over any interval of time gives the during that interval

Based on the concept of the wave-like nature of light, huygens' theory of light postulates that the more light was "bent" by a substance the slower it would move while traversing across that substance. a) deflection b) interference c) refraction d) resonance